The present invention relates to a new and distinct variety of evergreen perennial Eucalyptus cladocalyx, which has been named ‘EUC78’. Eucalyptus cladocalyx is an Australian native tree that grows to a mature height usually from 10 to 20 meters tall and 5 to 10 meters wide and is used as an ornamental tree in landscape and amenity horticulture. The common name of this species is ‘Sugar Gum’. The novel variety described herein details a red purple foliar form which is distinct from the common green foliar form. It has distinctive leaf and stem coloration including immature leaves and stems and bark as well as mature leaves, stems and bark.
An application for plant breeders' rights for ‘EUC78’ has been lodged with the Australian Plant Breeders Rights Office, and was received on 26 Mar. 2008 (under application No. 2008/084). An application for an Australian patent has been lodged with IP Australia and was filed on 16 Feb. 2009 under application number 2009900631.
Parentage: The cultivar ‘EUC78’ was discovered in 2005 in St Agnes, Adelaide, South Australia. The parent form is characterized by its dull green foliage color. Seed from open pollinated Eucalyptus cladocalyx (unpatented, common form) were sown and 2000 seedlings were germinated and grown on. The resultant seedlings were monitored on a regular basis and one of the seedlings was observed to exhibit a red purple foliage color which was different to the dull green foliage color of the other seedlings. The selection criterion for ‘EUC78’ was this novel red purple foliar coloration. This seedling was isolated and potted into a 50 mm tube for further growth and observation of its characters. It was found that the red colored immature leaves matured to a darker purple intermediate leaf color. The color of the stem was also found to be a dark purple color which remained as a stable trait as the plant grew to a larger size.
These foliar characters were observed to remain stable as the plant matured. Plants produced sexually by seed propagation are known to show variation in morphological characters. A stable method of reproducing the invention was developed by using an asexual method of propagation known as grafting, whereby shoots of the inventive plant are grafted to E. cladocalyx rootstocks. Cutting propagation of the variety may also be used to reproduce the invention.
The inventive variety was recognised to have merit for use as an ornamental tree in landscape and amenity horticulture with the plant being grown in a range of container sizes including 200 mm pots which are suited to supply the retail nursery market and larger container sizes, typically 300 mm to 800 mm, or bag sizes from 25 L to 400 L for the commercial landscape market.
The potential of the inventive variety as a cut foliage for the floral industry was recognised and branches can be used for this purpose. Vase life trials were conducted to establish this suitability and it was found a vase life of 5 to 12 days may be expected, depending on treatment and environmental conditions. The novel coloration of the inventive variety was considered to be a means of negating the need for traditional dye treatments as used in the floral industries.
Asexual reproduction. The new variety ‘EUC78’ was first asexually propagated by grafting in the state of New South Wales, Australia in 2006. The distinctive characteristics of cultivar ‘EUC78’ have remained stable and true to type through successive cycles of asexual propagation. Cutting propagation of the variety may also be used to reproduce the invention.